In order to decelerate rotating and/or slewing gears in construction machines, as is generally known, at least one dynamic brake and one static holding brake are used. With the dynamic brake, the rotational motion of the rotating gear, which is for example connected to a revolving superstructure of a mobile crane, can be decelerated in a controlled manner. With the holding brake, the rotating gear is locked at standstill.
When the dynamic service brake is actuated (for example via a brake pedal or a control lever or the like), a signal is generated that is evaluated by a controller. Taking into account additional parameters, such as rotational speed, load condition and/or load distribution, the controller controls the actuating elements, such as, for example, the hydraulic pumps and hydraulic valves, in order to decelerate the rotating gear. After the rotating gear has been brought to a standstill, it can be held in its current position by the connecting an additional static holding brake.
These types of arrangements and braking techniques have proven effective, however, they have the disadvantage that if the dynamic brake fails, there may not be a possibility of carrying out regulated emergency braking of the rotating and/or slewing gear, and in that way enabling a controlled deceleration of the revolving superstructure and/or of a boom. Because if the static holding brake is additionally connected, for example during the rotational movement of the rotating gear, this may lead to an abrupt stop of the rotating gear, and thus to a halt of the rotational movement of the revolving superstructure connected to the rotating gear.
Generally used as holding brakes are multiple-disk brakes that are comprised of a plurality of disks positioned consecutively on an axis, and which are non-rotatably connected to the fixed, or as the case may be, to the rotating part of the construction machine. These types of brakes have proven effective, however, they have the disadvantage that in the event of an abrupt stop of the rotating or slewing gear, the components of the construction machine itself can be seriously damaged, or, for example, uncontrolled swinging of the load attached to the boom can occur.
It has been shown that, given the design of the holding brake, safe braking of the rotating and/or slewing gear using the holding brake may not be possible. In an emergency, for example if the dynamic brake fails, the static holding brake can additionally be engaged during the rotating, or as the case may be, pivoting movement. This results in an abrupt interruption of the rotating or pivoting movement. This leads to shocks, and thus to increased wear on the rotating and/or slewing gear, and in the worst case, to the construction machine being destroyed.
It is therefore an object of the present invention to provide a device that overcomes the disadvantages described above, it then being possible, using said device, to ensure, even under operational conditions, safe and rapid braking of rotating and/or slewing gears in any installed configuration of a work machine. Another object is to provide a device which will, in the event of failure of the dynamic brake, ensure safe braking of rotating and/or slewing gears.